2.7 might be a bit low.. I'm getting 1.9MH x15 / each R9 270...
Try a lower worksize maybe? I had to drop mine to 64
I've tried it with 64, 128, and 256 work size. No notable difference.
Did u test it with "hamsi-expand-big" : "1", ?
Yes, absolutely. Also with "4". No change.
Same here ((( Absolute no difference for thread-concurrency, work-size and hams-expand-big ... just 2784 KH/s fro ASUS and 2733 for Gigabyte, but stable with 0 HW )))